INAPPROPRIATE ANTICHOLINERGIC MEDICATION USE IN ELDERLY PATIENTS

OBJECTIVES: The purpose of this study was (i) to determine the prevalence of inappropriate anticholinergic medication use in the elderly in general and elderly with dementia patients in specific (ii) to determine the predictors of inappropriate anticholinergic medication use in the elderly (iii) to determine the predictors of inappropriate anticholinergic medication use in elderly dementia patients METHODS: Retrospective cross-sectional study design was conducted using the 2009-2010 Medical Expenditure Panel Survey (MEPS) data, a nationally representative data on the community dwelling, non-institutionalized US population to determine the prevalence and predictors of inappropriate anticholinergic medication use in elderly and elderly dementia patients. The study sample for the first and second objective included patients aged ≥65 years whereas the study sample for the third objective included patients aged ≥65 years with a diagnosis of dementia. The inappropriate anticholinergic drugs were identified using revised 2012 American Geriatrics Society (AGS) Beers criteria. Weighted descriptive statistics were used to estimate the prevalence of inappropriate anticholinergic medication use in the elderly and elderly dementia patients. Multiple logistic regression within the conceptual framework of Anderson Behavioral Model was used to identify predictors associated with the use of inappropriate anticholinergic medications in the elderly and elderly dementia patients. Use of inappropriate anticholinergic medication as defined by the Beers’ criteria was the dependent variable. The independent variables were various predisposing, enabling, and need characteristics. RESULTS: Analysis of 2009 - 2010 MEPS data revealed that an estimated 78.60 million (95% CI: 73.71 to 83.49) were elderly participants (12.78% of US population); of which, 7.51 million (95% CI: 6.64 to 8.38) reported using inappropriate anticholinergic medications for an overall prevalence of 9.56%. The most frequently prescribed drugs among the elderly were found to be cyclobenzaprine (2.08%), promethazine (1.75%), amitriptyline (1.47%), hydroxyzine (0.95%), and dicyclomine (0.84%). Of the predisposing factors, the odds of receiving inappropriate anticholinergic drugs in elderly were significantly lower for patients between 75 to 84 years of age (OR: 0.64; 95% CI: 0.49 – 0.85) compared to the reference group, 65 to 74 years of age. Further, the odds of receiving inappropriate anticholinergic drugs in elderly were significantly much lower for patients >=85 years of age (OR: 0.52; 95% CI: 0.33 – 0.81) compared to the reference group, 65 to 74 years of age. The odds of receiving inappropriate anticholinergic drugs in the elderly were significantly higher for female patients (OR: 1.37; 95% CI: 1.06 – 1.77) compared to the male reference group. Also, the odds of receiving inappropriate anticholinergic drugs in the elderly were significantly lower for patients having >15 years of education (OR: 0.54; 95% CI: 0.35 – 0.84) compared to the reference group, <12 years of education. Of the enabling factors, the odds of receiving inappropriate anticholinergic drugs in elderly were significantly higher for patients who resided in the South region (OR: 1.88; 95% CI: 1.25 – 2.84) compared to the reference group, Northeast. Among the need factors, elderly patients suffering from anxiety (OR: 2.15; 95% CI: 1.57 - 2.94) were more likely to use inappropriate anticholinergic drugs. A total of 3.78 million (95% CI: 3.17 to 4.38) elderly patients were found to have been diagnosed with dementia for an overall prevalence of 4.81%. Of those, 1.02 million dementia patients (95% CI: 704,993 to 1,330,606) were reported to use inappropriate anticholinergic medications for a prevalence of 26.95%. Among the elderly dementia patients, the most frequently prescribed drugs were found to be oxybutynin (4.54%), solifenacin (4.48%), paroxetine (2.81%), tolterodine (2.47%) and promethazine (2.41%). Of the predisposing factors, the odds of receiving inappropriate anticholinergic drugs in elderly dementia patients were significantly lower for patients between 75 - 84 years of age (OR: 0.35; 95% CI: 0.15 - 0.81) compared to the reference group, 65 - 74 years of age. Of the need factors, the odds of receiving inappropriate anticholinergic drugs in elderly dementia patients were significantly higher for patients having fair/poor general health status (OR: 5.09; 95% CI: 1.36 - 19.08) compared to the reference group, patients having excellent general health status The odds of receiving inappropriate anticholinergic drugs in elderly dementia patients were significantly higher for patients suffering from anxiety (OR: 3.02; 95% CI: 1.21 - 7.54) and patients suffering from mood disorder (OR: 4.15; 95% CI: 1.87 - 9.22). None of the enabling factors were significantly associated with the use of inappropriate anticholinergic drugs in elderly dementia patients. CONCLUSIONS: The study found that approximately one in ten elderly patients used inappropriate anticholinergic medications. Female gender, south region and anxiety increased the likelihood of receiving inappropriate anticholinergic medications whereas age between 75 to 84 years, age >=85 years and >15 years of education decreased the likelihood of receiving inappropriate anticholinergic medications. However, the study found that approximately one in four elderly dementia patients used inappropriate anticholinergic medications. While, fair/poor general health status, anxiety and mood disorder increased the likelihood of receiving inappropriate anticholinergic medications, age between 75 to 84 years decreased the likelihood of receiving inappropriate anticholinergic medications. Drugs with anticholinergic properties are associated with central and peripheral adverse effects in vulnerable elderly populations. Hence, there is urgent need to optimize anticholinergic use in elderly patients. Both educational and regulatory approaches are needed to improve inappropriate prescribing practices to optimize appropriate anticholinergic medication use in elderly as well as elderly dementia patients.